The fuel depot is the Department of Defense's largest single-site fuel terminal in the United States. The depot provides military-grade fuel, lubricants and additives to U.S. Navy and Coast Guard vessels, and to those from allied nations like Canada.

The depot currently stores 1.8 million barrels of fuel. That's more than 75 million gallons, or roughly 1,200 gas stations worth of fuel, Schmitt estimated.

The Navy hopes to replace all of its 29 underground concrete fuel storage tanks, nine of which hold diesel fuel marine and 20 of which hold carrier jet fuel, which date back to when the installation began service in the early 1940s.

"This is the culmination of multiple years of planning by us and our engineering contractor partners," Schmitt said. "The infrastructure is 75 years old. The maintenance on these underground concrete tanks is a lot."

Schmitt said the tanks have to be inspected, cleaned and repaired at least once every 10 years, which costs $2 million to $3 million each per tank.

"The economics don't pencil out," Schmitt said.

The command also seeks to mitigate the potential risks of storing fuel underground.

"Underground storage tanks have inherent environmental risks and so we're trying to avoid those risks by bringing the tanks above ground," Schmitt said.

Each of the six proposed new tanks will hold an estimated 5.25 million gallons of either carrier aircraft fuel or diesel fuel marine. The tanks will be at least one and a half times bigger than any of the installation’s current above ground storage tanks, Schmitt said.

Schmitt said the tanks will likely be connected to the installation's existing network of pipelines and pumps. While many of those pipelines are originals, Schmitt said "they are in awesome shape."

The tanks will come with new safety monitoring technology for incidents such as leaks and fire management.

The tanks will be installed in phases, and the Navy will begin to close and phase out the old underground tanks as the new ones become functional.

The new tanks will change how "we move fuel to the pier, how we manage the tanks. It'll change all of our environmental planning documentation. It'll change our plans for how we respond to worst-case spills," Schmitt said, "but all of those things that will change will be developed during the construction process."

The project is still in its preliminary stages, including drafting designs, conducting environmental studies and considering any seismic vulnerabilities.

"Things may yet change because we are still preparing a package to go before Congress," Schmitt said. "We intend to submit that sometime in the next year."

Although the funding for the project has not yet been secured, Schmitt estimated if things go according to plan, construction on the new tanks will begin around fiscal year 2021. It would take an estimated five to six years to complete the project at a cost of $150 million to $200 million.

Schmitt said the Navy will be in contact with the surrounding community and stakeholders for comment and input on the project. He said the benefits of the upgrades at the fuel depot will spill over into the installation's surrounding communities.

"It's going to have the impact of a large construction project in the community," Schmitt said. "There's going to be a lot of contractors, a lot of movement of material. There are going to be folks who are looking to go get dinner. They're going to need support."

But once the project is complete, "it will be invisible to the community because we'll be operating behind the fence, kind of like we are now."